A question about soil ph

I received a soil sample today which listed soil ph in 2 different ways.
 
pHcaci2 = 6.7
Equivalent water pH = 7.3
 
What is the difference?
 
Thanks in advance for any helpful explanations:
 
Bob Attaway

---------------------------------------------------------------------
Pumpkin-growing archives: http://www.hort.net/lists/pumpkins/
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE PUMPKINS
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index